Suppose the template DNA strand of a ʺmini-geneʺ has the base sequence TACCCGGATTCA. The anticodon of the tRNA that carries the first amino acid to the ribosome will be
A) AGU.
B) UAG.
C) UCA.
D) AUG.
E) UAC.

Question

Quizplus · Accepted Answer

The template DNA strand is TACCCGGATTCA, so the mRNA sequence transcribed from it would be AUGGGCCUAAGU. The first codon (AUG) codes for the first amino acid, and the anticodon that pairs with this codon on the tRNA is UAC. However, the question asks for the anticodon that carries the first amino acid, which is methionine (Met), and its codon is AUG. The anticodon is written in the 3' to 5' direction, opposite to the codon, so the correct anticodon for the tRNA carrying the first amino acid (methionine) is UAC, but due to the options provided and the nature of the question, the correct interpretation is that it seeks the anticodon complementary to the mRNA. Thus, the confusion arises from the interpretation of the question's wording. Given the options and re-evaluating the context, the correct answer aligns with the mRNA's start codon AUG, which is not directly listed as an anticodon option. The question's phrasing might have led to an initial misunderstanding. The correct approach is to identify the anticodon that pairs with the mRNA's codon, but the options and explanation seem to have mixed the direct answer. The anticodon corresponding to the mRNA sequence AUG (which codes for Methionine, the first amino acid in a protein) would indeed be UAC in a direct pairing scenario. However, the question's framing about the "first amino acid" and the provided options might lead to confusion, as it seems to ask for the anticodon matching the mRNA's start codon. Given the options, none directly represent the anticodon for AUG (which would be UAC in direct tRNA-mRNA pairing). The explanation aimed to clarify this misunderstanding, acknowledging the mix-up in interpreting the question's intent and the provided answer choices.

Suppose the Template DNA Strand of a ʺMini-Geneʺ Has the Base